The present invention relates to a substrate transferring apparatus for transferring a large-sized substrate such as an LCD substrate and to a substrate processing apparatus using the substrate transferring apparatus.
In the manufacture of liquid crystal displays (LCD), the LCD substrate, made of glass, is coated with photo resist liquid to form a resist film, and the resist film is exposed to correspond to a circuit pattern. This is referred to as developing process, that is, the circuit pattern is formed by the so-called lithography technique.
Conventionally, such a series of coating/developing processes is carried out by a system in which the respective processing apparatus for carrying out these processes are incorporated. In such a system, there is provided a transferring apparatus for transferring/receiving a substrate between the respective processing units for performing the respective processes such as a cleaning process, a coating process, a developing process, and a heating process.
Such a transferring apparatus is provided to be movable on a transferring path. Also, the transferring apparatus comprises a base member, which can be rotated and moved up and down in transferring/receiving the substrate to/from the processing unit, and a base support arm, which is movable back and forth to the base member so as to deliver the substrate.
Conventionally, there is used the substrate transferring machine having a structure in which a pair of support sections supports an outer peripheral part of the substrate, and a guide provided at each of the tip of the peripheral part and a base part holds the substrate.
On the other hand, in this type of transferring machine, a belt driving system is generally used as a driving mechanism for moving the support arm back and fourth. In the use of the belt driving system, however, particles are easily generated. If such particles adhere to the processing substrate, problems such as deterioration of device performance and reduction of yield are caused. In order to solve such problems, in Japanese Patent KOKAI Publication No. Hei 8-293535, there are provided a cover for covering the driving mechanism of the support arm and means for sucking in the cover.
By the way, the need for enlarging the size of the LCD substrate has recently been increased more and more. Specifically, there has been needed the size of the substrate, which is greatly enlarged to, for example, 830.times.650 mm from the conventional size of 650.times.550 mm. If the size of the substrate is greatly increased, deflection of the central portion thereof is increased sharply as compared with the conventional case in supporting the substrate by the support arm. Then, at the time of transferring and receiving the substrate, the strokes of the up and down motion must be increased with the sharp increase in deformation of the central portion. As a result, throughput is reduced, and a transfer error is easily caused.
Moreover, if the substrate is enlarged as mentioned above, a large-sized driving mechanism of the transferring apparatus is also needed and an amount of generating particles is increased. However, in the technique disclosed in the above-mentioned Japanese Patent Application KOKAI Publication Hei 8-293535, an absorbing path, that is, an exhausting path is provided at an end portion side of the base member. As a result, there is possibility that particles generated from the driving mechanism will be not always absorbed effectively when the substrate is enlarged.